The goal of SHARE-THPP, Thinking Health Programme-Peer delivery, is to develop an innovative, effective and sustainable approach for the delivery of an established psychological treatment that reduces the burden of depression in mothers in South Asia. We aim to address a key barrier to the scaling up of mental health interventions in LMIC, the lack of trained human resources, by adapting an existing evidence-based intervention so that it can be delivered by peer counsellors - experienced women living in the same community - in partnership with established community health workers (CHWs). The SHARE-THPP intervention will be developed through extensive formative research and piloting the intervention with peer counselors to evaluate the feasibility and acceptability of the the implementation of the intervention. The effectiveness of the resulting intervention will then be evaluated through randomised controlled trials in three diverse settings in South Asia: a) Through a cluster randomised trial in Rawalpindi, Pakistan (rural setting) involving 40 CHW supervisory zones and 444 mothers, with trained peer-counsellors delivering the intervention in group format in the 20 intervention zones b) Through an individual randomised trial in Goa, India (urban setting), involving 328 women randomised into intervention and control arms, with peer-counsellors delivering the intervention in individual format to the mothers randomised to the intervention arm. c) Through an exploratory randomised trial in Swat, Pakistan (disaster-affected setting) involving 60 women randomised into intervention and control arms, with peer-counsellors delivering the intervention in individual format to the mothers randomised to the intervention arm. The primary outcome is maternal depression evaluated at six months, and secondary outcomes include maternal disability and child health. All analyses will be intention to treat. The programme will include detailed process evaluation and qualitative interviews with a sub-sample of participants.